Decency is the quality of following accepted moral standards.
His sense of decency forced him to resign.
他的正派作风迫使他辞职。
have the decency
If you say that someone did not have the decency to do something, you are criticizing them because there was a particular action which they did not do but which you believe they ought to have done.
He didn't even have the decency to tell them in person.
他很没礼节,居然没亲自告诉他们。